#! /bin/sh

# -------------------------------------------------------------
# --- init
# -------------------------------------------------------------

# leave on error
set -e

# set program name and location:
call="$0 $*"
case $0 in
  /* ) script=$0 ;;
  *  ) script="`/bin/pwd`/$0" ;;
esac
bindir=`/usr/bin/dirname ${script}`
prog=`basename ${script}`


# -------------------------------------------------------------
# --- help
# -------------------------------------------------------------

DisplayUsage ()
{
${PAGER:-less} << EOF

NAME
  $prog  -  General Storage System : files
  

USAGE

  ${prog} ls [-l,--long] <filespec>
    
      -l, --long    : long listing including modes, times, sizes etc

  ${prog} get [-f,--force] [-m,--mkdir] <source-filespec> <dest-filespec>
  ${prog} put [-f,--force] [-m,--mkdir] <source-filespec> <dest-filespec>
  
      -f, --force   : overwrite existing destination files if necessary
      -m, --mkdir   : create destination directories if necessary

  ${prog} link [-f,--force] [-n,--new] <source-filespec> <link-filespec>
  ${prog} unlink <source-filespec> <link-filespec>
  
      -f, --force   : overwrite existing destination files if necessary
      -n, --new     : create new empty file if necessary


FILE SPECIFICATION

  A file specification follows the standard rules:
    aa/bb/c.d

  
GENERAL OPTIONS
  -v, --verbose   : display info on progress
  
EOF
exit 0
}


# err 'help text'
err ()
{
  echo "$1" 1>&2
}


# errit <exit-status>
errit ()
{
  err "$prog - ERROR - from : ${call}"
  err "$prog - ERROR - Use '$prog --help' for more info."
  exit $1
}


# -------------------------------------------------------------
# --- arguments
# -------------------------------------------------------------

options=''
task=''
filespecs=''

verbose=''

# extract arguments
for arg in "$@" ; do
  case ${arg} in
    -h | --help    ) DisplayUsage  ;;
    -v | --verbose ) verbose='T' ;;
    -* ) options="${options} ${arg}" ;;
    * ) # task or (one of the) file(s)
      if [ -z "${task}" ]; then
        task=${arg}
      else
        filespec=${arg}
        filespecs="${filespecs} ${filespec}"
      fi
      ;;
  esac
done

# not complete ?
if [ -z "${task}" ]; then
  DisplayUsage
  exit 1
fi


# -------------------------------------------------------------
# --- begin
# -------------------------------------------------------------

test ${verbose}  &&  echo "$prog - $prog $*"

# test task:
case ${task} in

  # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  # list file or directory
  # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

  'list' )

    # extract options
    ls_options=''
    for option in ${options} ; do
      case ${option} in
        -l | --long  ) ls_options="${ls_options} -l" ;;
        -* )
          err "$prog - ERROR - unknown option '${option}' for task '${task}'"
          errit 1
          ;;
      esac
    done

    # list files:
    /bin/ls ${ls_options} ${filespec}
  
    ;;

  # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  # copy files
  # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

  'get' | 'put' )

    # extract options
    cp_options=''
    do_mkdir=''
    for option in ${options} ; do
      case ${option} in
        -f | --force ) cp_options="${cp_options} -f" ;;
        -m | --mkdir ) do_mkdir='true' ;;
        -* )
          err "$prog - ERROR - unknown option '${option}' for task '${task}'"
          errit 1
          ;;
      esac
    done

    # extract source and destination filespec:
    source_spec=''
    dest_spec=''
    for spec in ${filespecs} ; do 
      if [ -z "${source_spec}" ]; then
        source_spec=${spec}
      elif [ -z "${dest_spec}" ]; then
        dest_spec=${spec}
      else
        err "$prog - ERROR - tasks 'get' and 'put' require source and destination file specifications only."
        errit 1
      fi
    done
    if [ -z "${dest_spec}" ]; then
      err "$prog - ERROR - tasks 'get' and 'put' require source and destination file specifications."
      errit 1
    fi
    
    # create destination directory ?
    #  o destination is an existing file : not necessary
    #  o destination is an existing directory : not necessary 
    if [ ${do_mkdir} ] && [ ! -f ${dest_spec} ] && [ ! -d ${dest_spec} ]; then
      # destination is not an existing file or directory;
      # create the directory part of the destination:
      dest_dir=`/usr/bin/dirname ${dest_spec}`
      test "${dest_dir}" != "."  &&  /bin/mkdir -p ${dest_dir}
    fi
    
    # copy file; suppress error messages:
    /bin/cp ${cp_options} ${source_spec} ${dest_spec} > /dev/null 2>&1
  
    ;;

  # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  # task ???
  # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

  * )
    err "$prog - ERROR - unsupported task '${task}'"
    errit 1
    ;;
  
esac  # tasks


# -------------------------------------------------------------
# --- end
# -------------------------------------------------------------

test ${verbose}  &&  echo "$prog - end"

# ok
exit 0